ADVANCE FOR MONDAY, FEB. 27, 2012 AND THEREAFTER - This Sept. 2011 photo provided by Vanguard Defense Industries, shows a ShadowHawk drone with Montgomery County, Texas SWAT team members. Unmanned military aircraft have tracked and killed terrorists in the Middle East and Asia. Their civilian cousins are now in demand by police departments, border patrols, power companies, news organizations and others wanting a bird's-eye view that's too impractical or dangerous for conventional planes or helicopters to get. Along with the enthusiasm, there are qualms. Drones overhead could invade people's privacy. The government worries they could collide with passenger planes or come crashing down to the ground, concerns that have slowed more widespread adoption of the technology. (AP Photo/Lance Bertolino, Vanguard Defense Industries)

With our wars winding down and the domestic use of drones ramping up, the multibillion-dollar industry wants to upgrade its image as makers of assassins in the sky.

After all, these "unmanned aerial vehicles" can also play important roles as sophisticated map makers, aerial photographers, search and rescue aids and scientific tools.

Privacy advocates, however, are gravely concerned about another obvious domestic use: midair snoop.

Last month, President Obama signed a law that directs the Federal Aviation Administration to create a set of rules that clears the way for more use of drones by businesses and law enforcement. For years, the FAA has tightly restricted their use, for fear the vehicles could collide with aircraft, considerations that are sure to be the focus of the agency's study of the matter.

Broad category

Technically, unmanned aerial vehicles (some quibble with the word drone) are remote or autonomously controlled aircraft, a broad category that can encompass military-grade weapons as well as small do-it-yourself helicopters with cameras.

"They raise the prospect of bringing surveillance to a whole new level," said Jay Stanley, senior policy analyst at the ACLU.

Among other things, the letter noted that sophisticated drones can track up to 65 targets across 65 square miles. They can also carry high-definition cameras, heat sensors, automated license plate readers and, eventually, facial recognition technology.

The petition said that law enforcement agencies and private detectives have already begun to use them, and that paparazzi, criminals and stalkers could be next. It raised particular concerns about government use of drones, which make persistent surveillance cheap and enable law enforcement to stare through the windows and even walls that used to represent private domains.

Surveillance state?

Ryan Calo, director of privacy at Stanford's Center for Internet and Society, worries that drones could nudge us closer to a surveillance state, where police shift from responding to real crimes to indiscriminately hunting for infractions and suspicious behavior.

"I'm worried about the next phase of policing that's completely automated," he said.

At the same time, drones might be so different that they force a fundamental rethinking of privacy rights.

For all the clamoring over digital privacy invasions these days, with apps peeking at address books and advertisers tracking online activity, the dangers still feel largely abstract to many.

But we get - in an immediate and visceral way - what it means to have floating video cameras tracking our every move, Calo said.

"Drones come with their own psychological baggage," he said. "We think of them as inscrutable robots that we associate with targeted killing."

He argues it will only be a matter of time before test cases emerge that alarm citizens and judges, as drones observe people in settings we've traditionally considered private. If so, it could set broader precedents for what constitutes a reasonable search with drones or other controversial technologies, like GPS tracking, smart-phone monitoring and ground-based surveillance systems.

He argues, however, that there's a legal framework for dealing with the privacy concerns. Peeping Tom and other privacy laws restrict drones from spying into windows. In addition, Gielow said, Supreme Court cases have established that police need warrants for helicopter surveillance under certain conditions.

"There is already case law and history for how police can legally use these types of cameras and sensors," he said.

But in the cases he cited - Florida vs. Riley and California vs. Ciraolo - the majority concluded that the aerial observation in question didn't require a warrant. A line in the Riley decision suggested that police surveillance below 400 feet might violate reasonable expectations of privacy - and thus, one presumes, could require a warrant.

Fine details

But drones can observe in fine detail from well above that limit, so it's hard to see how the case satisfies the privacy concerns in question.

Addressing these concerns is important, but what shouldn't get lost in the debate are the many promising uses of drones, said Stephen Morris, president of the MLB Co., a Mountain View company that manufacturers unmanned aerial vehicles.